Rigid intubating laryngoscope with interchangeable blade and video display

ABSTRACT

An intubating laryngoscope providing a standard handle, ready interchangeability of standard blades, a camera, and a magnifiable video display for easier and safer use in efficiently positioning an endotracheal tube through the vocal cords of a patient into the trachea, and for recordation in order to teach the procedure and for legal purposes.

OF FIELD OF THE INVENTION

[0001] An intubating laryngoscope providing ready interchangeability of blades and a magnifiable video display for easier and safer use in efficiently positioning an endotracheal tube through the vocal cords into the trachea and teaching the procedure.

BACKGROUND OF THE INVENTION

[0002] In the United States, approximately 10 million patients are operated on and anesthetized each year. While anesthetized, the patient's breathing functions are temporarily disabled. Ventilation is therefore supplied to the patient by the anesthesiologist during the procedure.

[0003] Ventilation is provided through an endotracheal tube. This tube is inserted into the trachea, and it is closed against the wall of the trachea by an inflatable cuff. The insertion of this tube involves risks that the anesthesiologist seeks to avoid or at least minimize. It is estimated that between one in 8,000 to one in 10,000 general anesthesia procedures result in death. There are of course many causes but of these it is estimated that about one third of them are caused by the intubation procedure.

[0004] The foremost obstacles that the anesthesiologist encounters are; the remoteness of the location where the tube is to be positioned, the consequent restriction of view as the tube is inserted, variations and anomalies in the anatomy of the patients, an uncomfortable and unnatural position for the anesthesiologist while holding the instrument, the potential need to change blades during the procedure, and the necessity for rapid intubation.

[0005] It should be remembered that when the tube is to be inserted, the patient is asleep, and when he/she had been paralyzed for the procedure he/she is not breathing and the ventilator is not yet in operation. This gives the anesthesiologist only about two minutes in which to intubate the patient, inflate the cuff, and start ventilation. If he is delayed by the need to change blades of conventional instruments or by clumsiness of the instrument, he must stop, apply a ventilation mask to the patient, supply oxygen for a time through the mask, remove the mask, adjust medication if necessary, and then start over again. This delays the operation and extends the patient's time under anesthesia. This extension of time while under anesthesia may have very serious consequences, especially for elderly patients.

[0006] However, the need for rapid intubation cannot be permitted to expose the patient to greater risk. Severe damage can be done to the larynx and vocal cords by a intubation tube if it makes inappropriate contact with them. The objective, is to pass the tube through the vocal cords well aimed and smoothly where it will do no damage, namely directly between the vocal cords and avoid multiple unsuccessful attempts.

[0007] The direct visualization of the vocal cords through an open tube, which was the standard instrumentation for many years, gave only a limited and very unsatisfactory view of the region. It was like peering through a small keyhole into a dimly lit region. Furthermore, it required the anesthesiologist to assume a most inconvenient posture while peering through the instrument, manipulating it with one hand, and pushing and turning the tube with the other. In practice it often required a “third hand” to apply laryngal pressure, which is often used. The literature and conversation in this field often refers to a third hand; (i.e. the need for an assistant).

[0008] With the advent of endoscopic equipment and small cameras, instrumentation has been improved to the extent that it can enable viewing of the magnified cords and the larynx anatomy on a video screen. This in itself was a great advance in the field.

[0009] However, conventional instrumentation still fails to provide the anesthesiologist with an instrument which as to him is entirely standard and requires no special training, providing an optimal video display with a full field of view that is enlarged and can be fully utilized with the use of only two hands, and in which blades can be changed quickly to account for the anatomical structure of the individual patient. Additionally, conventional instrumentation still fails to provide the anesthesiologist with an instrument with which teaching and training can be accomplished, and records and instructional videos compiled.

[0010] It is an object of this invention to provide such an instrument with these stated advantages, especially those of accuracy, familiarity, and efficiency.

SUMMARY OF THE INVENTION

[0011] An instrument according to this invention includes a standard handle for the anesthesiologist to hold, a camera, standard blades each having a configuration appropriate to a specific anatomical configuration, and a separable hinge type joinder having a portion on the handle and on each blade, the handle and the blades together forming a standard configuration familiar to all anesthesiologists trained in this procedure.

[0012] According to a feature of this invention, a cable guide tube extends along each said blade from a location adjacent to said joinder to a location near the tip of the blade. A flexible cable extends freely from the handle. It is inserted into the cable guide tube when the blade is attached to the handle. It is correctly positioned where the joinder is closed.

[0013] The cable itself conducts light to illuminate the field ahead of the tip of the blade. The cable also includes a means to convey an image or data respective to an image of the region. When the camera is built into the handle, the means in the cable is a coherent fiber optic bundle. When the camera is placed at the end of the cable, the means is a conductive lead.

[0014] In either arrangement, the illumination and image bearing means are carried by the cable respectively to illuminate and obtain the image of the region.

[0015] A plurality of blades can be attached to the instrument in the standard fashion known to anesthesiologists in the field. Every blade has a light bulb or light fiber carrier, which in this case is replaced with an open steel tube or guide tube. In this guide tube, the image and light bundle are inserted to stay in position. A small oxygen tube is welded in the blade which can be connected to an oxygen source and oxygen administered. This serves as defogging and increases oxygenation of the patient.

[0016] The light source may be a conventional battery and light bulb arrangement carried in the handle, or according to a preferred feature of the invention it may be a separate light source placed a convenient distance away and connected to the handle by a light-transmitting fiber optic bundle. With the use of this bundle, which may pass around the anesthesiologist, there is no interference with his movements or with the free advancement of the endotracheal tube.

[0017] The video display receives the image signal from the camera through a lead that extends from the handle. When an external light source is used, its fiber optic bundle will also exit from the handle. The lead and the bundle can conveniently exit from the back of the handle and pass around the anesthesiologist. The video display, projected on a monitor placed above the chest of the patient by a swing arm, provides for magnified images of the fields of view, which is very important in order to easily and quickly perceive the anatomical region or anomalies.

[0018] One of the most important aspects of the invention is that the instrument is to be used in the manner of a standard laryngoscope therefore no additional training is necessary, however, there is no longer the need to place the endotracheal tube in a semi-blind fashion through the “keyhole” vision of the standard laryngoscope.

[0019] The above and other features of this invention will be fully understood from the following detailed description and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0020]FIG. 1 is a side view of a handle according to this invention;

[0021]FIG. 2 is a left hand view of FIG. 1;

[0022]FIG. 3 is a side view of a blade useful in this invention;

[0023]FIG. 4 is a cross-section taken at line 4-4 in FIG. 3;

[0024]FIG. 5 is a cross-section taken at line 5-5 in FIG. 1;

[0025]FIG. 6 is a side view, partly in schematic and partly in cross-section showing the system of the invention;

[0026]FIG. 7 is a side view of another useful blade;

[0027]FIG. 8 is an axial cross-section of an optional cable and guide assembly;

[0028]FIG. 9 is a cross-section taken at line 9-9 in FIG. 8; and

[0029]FIG. 10 is an axial section partly in schematic notation showing an alternate camera arrangement.

DETAILED DESCRIPTION OF THE DRAWINGS

[0030]FIG. 1 illustrates an intubating laryngoscope 10 according to this invention. This includes a handle 11, which customarily is cylindrical with a knurled outer surface for a secure grip. It is shown in FIG. 6 detachable joined to a curved blade 12 by a hinge-type joinder 13.

[0031] The blade 12 illustrated in FIGS. 3 and 5 is a curved blade, which is used to elevate the tongue in some circumstances. A different blade 15 for a different anatomical configuration is a straight blade adapted for use in other circumstances is shown in part in FIG. 7. These are the well-known McIntosh and Foregger-Magill blades. These are the two most common blade shapes. Their configuration, however, is not a limitation on the invention. The configurations of this handle and these blades are completely conventional. They are standard equipment utilized by anesthesiologists trained to intubate the trachea. An advantage of this invention is that it does not require any additional training or re-training of anesthesiologists who have used it or will in the future utilize it.

[0032] The hinge-type joinder 13 includes a pair of conventional hinge portions 20, 21 respectively mounted to the lower end of the handle and of the proximal end of the blade. Portion 20 is a socket 22 having a crossbar 23. Portion 21 has a hook 24 in a block 25 that fits in the socket. The hook engages the rod, and the handle is rotated 90 degrees so that the blade will be rigidly held to the handle. This is a common hinge-type joinder used in this type of instrumentation and is useful for all blade forms, of which the two illustrated forms are merely examples. A ball detent 27 releasablely retains the portions together and erect in the assembled configuration. The assembled instrument is rigid during the procedure.

[0033] Curved blade 12 has a distal end 30 which may be smoothed by a bulb-like edge 31. It has a curved top surface 32 extending from the distal end toward the proximal end. This surface is used to elevate the tongue and permit the visualization of the vocal cords beneath it.

[0034] Blade 12 additionally includes a cable guide tube 35. At its proximal end it has an enlarged funnel-like entry portion 36. The guide tube is fixed to the blade and terminates near the distal end of the blade for reasons, which will be forthcoming. The entry portion 36 terminates near the joinder.

[0035] The handle is provided with means for obtaining an image of the field located beyond the tip of the blade, and for providing light to that field. In the presently preferred embodiment, a camera 40 (FIG. 6) is mounted in a chamber 44 inside the handle.

[0036] A cable 41 to conduct the image data from the camera and in some embodiments brings illuminating light to the handle, exits from the top of the handle. It is connected to a video set 42, which provides data for an image on a video screen 43, for observation by the anesthesiologist.

[0037] The video set also provides for magnification of the image so that it is easier to discover anomalies or guide the endotracheal tube safely and quickly through the vocal cords. Because of the enlarged view, the unnecessary poking and pushing of the larynx is avoided. This is important to eliminate refluxes, which can result in hemodynamic changes, which are important to avoid, especially in patients with cardiac disease or bleeding from this area.

[0038] It is important that a true video screen be used rather than a PC screen. This is because a PC screen can effectively be viewed no more than a few degrees off of the perpendicular to the screen, and thereby constitutes a limitation on the freedom of the anesthesiologist's head movement. In addition, their resolution and brilliance are insufficient for effectively viewing minute details by a very busy anesthesiologist. The video set can be mounted on a swing arm and the monitor placed above the patient's chest, providing the anesthesiologist with a clear view but on the same axis as the manipulation facilitating the intubation. This maneuver is not a static process and if the anesthesiologist has to move his head, the eye-hand coordination with our monitor position allows clear view from various angles not possible with LCD screens.

[0039] In the preferred embodiment of the invention, light for illumination is obtained from a separate light source 50 that can be placed in any convenient nearby location. A fiber optic bundle 51 extends from the light source to the handle, conveniently in cable 41. Both enter chamber 44 in the handle where the camera is located.

[0040] As a feature of this invention, a flexible cable 55 exits freely from the handle near its lower end. This cable should be inserted into the guide tube when the blade is joined to the handle. Its free end can quickly and easily be inserted into the guide tube and advanced into it so that its free end is exposed to and directed toward the region below and ahead of the distal end of the blade. A slack bend 56 in the cable enables the cable to bend when the handle is pivoted relative to the blade in its hinge-like movement. Similar provisions are incorporated in all blades used in the invention.

[0041] The actual construction and content of cable 55 depends on the arrangement of the camera and of the light source. In the preferred embodiment shown in FIG. 6, camera 40, customarily a CCD chip, is mounted to the handle inside chamber 44. Then the cable will include a fiber optic bundle 57 of coherent strands, which extend from an objective lens 60 at its distal end to the camera. This will convey an image to the camera.

[0042] A lead 61 from the camera (conveniently housed in cable 41) carries the data to a television set 62. This lead exits from the end of the handle as part of cable 41 and passes around the anesthesiologist or to his side so as not to interfere with the anesthesiologist's movements.

[0043] For illumination purposes a second fiber optic bundle 63 is provided in cable 55. It is optically coupled to bundle 51 and is in effect a continuation of it. Bundle 63 need not be coherent, because it does not transmit an image it transmits only light. The light is directed from its distal end to the field of view.

[0044] It will now be seen that joining the blade to the handle and completing the assembly of light and image means is a swift process. The end of cable 55 is merely advanced into the funnel-like open end 36 of guide tube 35, the portions of the joinder are engaged, and the instrument is ready for use. Removal is quick—merely remove the image light bundle from the guide tube, release the blade, and pull the handle away from the blade. Removal and replacement are very simple.

[0045] If desired, an oxygen-carrying conduit 65 (FIG. 4) may be attached to the blade, discharging a slow stream of oxygen across the objective lens to prevent its fogging-up and increases oxygenation of the patient.

[0046] Blade 15 (FIG. 2) differs from blade 12 only by its shape. It has a straight upper surface 708 instead of a curved surface for use when such a surface is preferred for lifting the tongue of the individual patient. In all cases the objective is to lift the tongue to permit visualization of the vocal cords and to enable the endotracheal tube to be accurately placed without harming surrounding tissue in the process.

[0047] Instead of the camera and illumination arrangements already described, there are other alternatives, which can be used in any combination, such as locating the light source in the handle. However, the principal advantage of the use of a separate light source is that the handle can be made thinner, and the instrument made lighter.

[0048] In the preferred embodiment the camera will be placed in the handle as already described. However, it is equally feasible to place a camera 65 at the end of the cable as shown in FIG. 10. In this situation the cable 55 will carry, instead of a coherent fiber optic, leads 66 conveying the camera data output from the camera to the handle, and through the handle to cable 41 and then to the video set.

[0049] Notice that in every situation the cable from the handle to the blade is flexible, passes into the guide, and is thereby accurately placed for use. When the blade is separated from the handle, the cable is simply pulled out of the tube and accompanies the handle.

[0050] The display may be improved by eliminating the raster pattern form the image by use of apparatus 67 shown in U.S. Pat. No. 5,751,340, which will be interposed between the set and the display. This patent is made a part hereof by reference in its entirety for its showing of a useful system for this purpose however, its use is optional.

[0051] All existing conventional blades, which provide illumination, include a tube that will hold the illumination means in place, for example fiber optic bundles. The guide tube of this invention may be directly substituted for them. There is a useful optional improvement shown in FIGS. 8 and 9. In this embodiment, instead of a permanently installed guide tube, a clip such as clip 70 (FIG. 3) is provided. Then a plastic tube 71 with an acrylic window 72 and a funnel-like guide 73 is clipped in place as in FIG. 3. The plastic guide tube is pre-sterilized and then discarded after the procedure so that the bundle does not have to be cleaned, but the blade, which was in the patient's mouth, can be washed, disinfected or even autoclaved.

[0052] A vivid display is observable form a wide angle, which facilitates training. The trainer can easily observe the trained student and his work, and guide him. Without such a display, the instructor cannot see what the trainee is doing. With a magnified video view, both the student and the trainer have a simultaneous view of what the trainee is doing.

[0053] This system lends itself to recordation for legal purposes, as well as providing a library for training students while they are not under the direct supervision of the instructor. In the United States there are about 150 teaching programs in institutions, and about 30,000 anesthesiologists. Library-type video tapes are a particularly valuable means to reach the very large number of anesthesiologists who are years from their student days, and who have little opportunity for direct-participation in re-education for such a fundamental procedure.

[0054] This invention is not to be limited to the embodiments shown in the drawings and described in the description, which are given by way of example and not of limitation, but only in accordance with the scope of the appended claims. 

What is claimed is:
 1. An intubating laryngoscope system providing for ready interchange of blades, for video display, and for convenience in use comprising: a handle to be held by an anesthesiologist; a blade having a surface configured to enable the anesthesiologist to elevate the tongue of a patient, a proximal end, and a distal end; a hinge-like joinder separably to join said handle and said blade, said joinder having a first portion on said handle and a second portion on said proximal end of said blade, one of said portions having a rod and the other portion having a hook, whereby in an engaged orientation the hook and the rod are engaged, and in a released configuration they may be separated, the handle and blade being rigidly attached to one another in the engaged orientation; a flexible cable extending from said handle having a fixed end fixed to the handle, and a free end; a guide tube attached to said blade, extending from near the proximal end of the blade toward its distal end, said guide tube including an enlarged a funnel-like entry portion to facilitate the entry of said flexible cable into said guide tube, the length of said flexible cable being such that when the handle and blade are in the engaged orientation, the flexible cable is disposed in a predetermined position in the blade; a camera; a light source; a light-transmitting fiber optic in said flexible cable; image-transmitting means in said flexible cable; a second cable extending from said handle; a video receiver connected to said second cable receptive to signals from said camera; and a video screen receptive to said video receiver to display images transmitted from said camera.
 2. A system according to claim 1 in which said camera is disposed in a chamber in a said standard handle, and said image-transmitting flexible cable comprises a coherent fiber optic bundle having one end exposed to a field of view and a second end exposed to said camera.
 3. A system according to claim 1 in which said light source is separate from the handle, and in which said light-transmitting fiber optic is adapted to receive light from said light source to be transmitted to the field of view.
 4. A system according to claim 3 in which said camera is disposed in a chamber in said standard handle, and said flexible cable includes a coherent fiber optic bundle having one end exposed to a field of view and a second end exposed to said camera.
 5. A system according to claim 1 in which said camera is mounted to the distal end of the flexible cable, and the image-transmitting means is a lead which conveys image data through said handle to said video receiver.
 6. A system according to claim 1 in which said light source is a battery and bulb combination in said handle to provide light to said light-transmitting means.
 7. An intubating laryngoscope system enabling relay interchange of blades, video display, and convenient use, comprising: a handle to be held by an anesthesiologist; a blade having a surface configured to enable the anesthesiologist to elevate the tongue of a patient, a proximal end, and a distal end; a hinge-like joinder separably to join said handle and said blade, said joinder having a first portion on said handle and a second portion on said proximal end of said blade, one of said portions having a rod and the other portion having a hook, whereby in an engaged orientation the hook and the rod are engaged, and in a released configuration they may be separated, the handle and blade being rigidly attached to one another in the engaged orientation; a flexible cable extending from said handle having a fixed end fixed to the handle, and a free end; a guide tube attached to said blade, extending from near the proximal end of the blade toward its distal end, said guide tube including an enlarged funnel-like entry portion to facilitate the entry of said flexible cable into said guide tube, the length of said flexible cable being such that when the handle and blade are in the engaged orientation, the flexible cable is disposed in a pre-determined position in the blade; a camera; a light-transmitting fiber optic in said flexible cable; image-transmitting means in said flexible cable; and a second cable extending from said handle; and said second cable being adapted to be connected to a video receiver which is receptive to signals from said camera.
 8. A laryngoscope according to claim 7 in which said camera is disposed in a chamber in said standard handle, and said image-transmitting flexible cable comprises a coherent fiber optic bundle having one end exposed to a field of view and a second end exposed to said camera.
 9. A laryngoscope according to claim 7 in which said light transmitting fiber optic in said flexible cable is adapted to receive light from a separate light source to be transmitted to the field of view.
 10. A laryngoscope according to claim 9 in which said camera is disposed in a chamber in said standard handle, and said flexible cable includes a coherent fiber optic bundle having one end exposed to a field of view and a second end exposed to said camera.
 11. A laryngoscope according to claim 7 in which said camera is mounted to the distal end of the flexible cable, and the image-transmitting means is a lead from said camera extending through said handle for conveying image data through said handle to a video receiver.
 12. A laryngoscope according to claim 7 in which said light source is a battery and bulb combination in said handle, to provide light to said light-transmitting means.
 13. A system according to claim 1 in which said guide tube has a closed distal end with an optically clear and transparent window at said distal end, and a wall extending to said entry portion, said wall and said window being imperforate and sterilizeable, whereby a non-sterile and flexible cable can be inserted into said guide tube, and the guide tube disposed of after use without need to sterilize the flexible cable before its next use.
 14. A laryngoscope according to claim 7 in which said guide tube has a closed distal end with an optically clear and transparent window at said distal end, and a wall extending to said entry portion, said wall and said window being imperforate and sterilizeable, whereby a non-sterile said flexible cable can be inserted into said guide tube, and the guide tube disposed of after use without need to sterilize the flexible cable before its next use.
 15. A system according to claim 1 in which a device to remove the geometric pattern from the signal to the video screen receives and processes the image signal form the camera.
 16. A laryngoscope system according to claim 1 in which a conduit mounted to the blade with an exit opening near the distal end of the flexible cable is adapted to discharge a stream of oxygen adjacent to the distal end of the guide tube.
 17. A laryngoscope according to claim 7 in which a conduit mounted to the blade with an exit opening near the distal end of the flexible cable is adapted to discharge a stream of oxygen adjacent to the distal end of the guide tube. 